Fluid sterilization device

Abstract

This invention provides a fluid sterilization device that effectively utilizes the wide-angle ultraviolet light emitted and allows the fluid to remain in the irradiated area. [Solution] A fluid sterilization device comprising: a first flow channel section 10 through which fluid passes from one end 11 to the other end 12; a light source unit 20 connected to the other end of the first flow channel section and irradiating the fluid with ultraviolet light; a second flow channel section 30 opposite the first flow channel section with the light source unit in between; and a third flow channel section 40 disposed radially outward from the light source unit for directing the fluid flowing in the first flow channel section to the second flow channel section. The first flow channel section or the light source unit is provided with a first communication section 121 communicating with the third flow channel section, the second flow channel section or the light source unit is provided with a second communication section 311 communicating with the third flow channel section, the first communication section is provided with multiple communication areas cut out from the connection between the first flow channel section and the light source unit, the second communication section is provided with multiple communication areas from the connection between the second flow channel section and the light source unit, and the communication areas in the first communication section and the communication areas in the second communication section are arranged alternately in the circumferential direction.

Description

Technical Field

[0001] The present invention relates to a fluid sterilization device.

Background Art

[0002] Various products that sterilize fluids (for example, liquids for beverages or raw material water for foods, or various cooling waters and washing waters for factories) by irradiating ultraviolet light are provided. As inventions related to this, fluid sterilization devices provided in fluid flow paths are disclosed in, for example, Patent Documents 1 and 2 below.

[0003] Here, the fluid sterilization device disclosed in Patent Document 1 includes a straight tubular processing chamber extending from a first end face to a second end face, an inlet and an outlet connected to the side wall of the processing chamber, and light sources respectively disposed near (outside) the first end face and the second end face. The ultraviolet light irradiated from the light source passes through ultraviolet light transmission windows fitted into the first end face and the second end face. Thereby, it is possible to irradiate the fluid flowing near the inlet with ultraviolet light of higher intensity than the fluid flowing near the outlet.

[0004] Further, the fluid sterilization device disclosed in Patent Document 2 includes a first flow path extending in the longitudinal direction, a light source unit that substantially faces the first flow path and irradiates the fluid flowing through the first flow path with ultraviolet light, and a second flow path that is connected to the first flow path and formed around the light source unit. The fluid flowing through the second flow path flows from the surface (light emitting surface) side of the light source unit to the back surface (opposite surface to the light emitting surface) side.

[0005] Furthermore, Patent Document 2 discloses an aspect in which the inner diameter of the flow path at the connection portion between the first flow path and the light source unit is made smaller than the inner diameter of the first flow path, and an offset portion that is recessed inside the light source unit is provided in the region facing the first flow path of the light source unit. Thereby, the fluid flowing from the first flow path is collected in the offset portion, and by generating convection (eddy current) in the fluid collected in the offset portion, the fluid can be irradiated with ultraviolet light for a long time.

Prior Art Documents

Patent Documents

[0006] [Patent Document 1] Patent No. 6571460 [Patent Document 2] Japanese Patent Publication No. 2018-8213 [Overview of the project] [Problems that the invention aims to solve]

[0007] Incidentally, the irradiation range of ultraviolet light emitted from a light source includes not only the area facing the light source but also the area to the sides of the light source (ultraviolet light that reaches the area to the sides of the light source may be referred to as "wide-angle light" below). Therefore, if the fluid can be effectively irradiated with the aforementioned wide-angle light, the fluid can be sterilized more effectively. However, no means of using wide-angle ultraviolet light to enhance the sterilization ability of a fluid are disclosed or suggested in Patent Document 1.

[0008] Furthermore, in the fluid sterilization apparatus described in Patent Document 1, if ultraviolet light, including wide-angle light, is to be irradiated onto the fluid, the diameter of the processing chamber needs to be increased. However, in this case, the size of the processing chamber (fluid sterilization apparatus) becomes larger.

[0009] Furthermore, in the fluid sterilization device described in Patent Document 2, in order to generate convection in the fluid flowing near the light source unit, a complex structure must be provided in which the inner diameter of the flow path inside the connecting part is shorter than the inner diameter of the first flow path, and an offset part is provided in the light source unit. This may lead to a significant increase in the manufacturing cost of the fluid sterilization device.

[0010] In view of the above-mentioned problems, the present invention aims to provide a fluid sterilization device that can effectively utilize wide-angle ultraviolet light emitted from a light source unit and has an extremely simple structure while retaining fluid within the ultraviolet light irradiation range. [Means for solving the problem]

[0011] To solve the aforementioned problems, the fluid sterilization apparatus according to the present invention is A first flow channel section extending in the axial direction, through which fluid passes from one end to the other, A light source unit is connected to the other end of the first flow channel and irradiates the fluid with ultraviolet light, A second channel section opposite the first channel section, with the aforementioned light source unit in between, The light source unit is provided with a third flow channel, which is arranged radially outward from the light source unit and is for directing the fluid flowing in the first flow channel to flow in the second flow channel, The first flow channel or the light source unit includes a first communication section that communicates with the third flow channel, The second flow channel or the light source unit is provided with a second communication section that communicates with the third flow channel, The first communication section comprises a plurality of notched communication areas cut out from the connection section between the first flow path section and the light source unit. Furthermore, the second communication section includes a plurality of notched communication areas that are cut out from the connection section between the second flow path section and the light source unit. The notched communication area in the first communication section and the notched communication area in the second communication section are arranged alternately in the circumferential direction.

[0012] According to this aspect of the present invention, a third channel is provided that communicates with both the first and second channel sections and is arranged radially outward of the light source unit. As a result, the fluid flowing through the first channel section reaches the light source unit, then flows along the ultraviolet light emitting surface of the light source unit and toward the third channel section. This allows the wide-angle ultraviolet light emitted from the light source unit to irradiate the fluid flowing from the first channel section to the third channel section. Furthermore, the fluid flowing from the first channel section to the third channel section passes through the first communication section, which has a notched communication area. At that time, the fluid flows concentratedly into the notched communication area. As a result, turbulence is generated near the notched communication area, allowing the fluid to remain stagnant. Therefore, ultraviolet light can be irradiated onto the fluid flowing from the first channel section to the third channel section for a long period of time. This enhances the bactericidal capacity of the fluid. Furthermore, since the notched communication zones in the first communication zone and the notched communication zones in the second communication zone are arranged alternately in the circumferential direction, short-circuiting of the fluid from the first channel to the second channel via the third channel can be effectively prevented. As a result, the fluid can be retained near the notched communication zone in the first communication zone, and the fluid can be irradiated with ultraviolet light for a long period of time. Consequently, the bactericidal ability of the fluid can be further enhanced.

[0013] Furthermore, in the fluid sterilization apparatus according to the present invention, The third channel portion is preferably made of polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), perfluoroalkoxyalkane (PFA), or polypropylene (PP). [Effects of the Invention]

[0014] According to the present invention, it is possible to effectively utilize the wide-angle ultraviolet light emitted from the light source unit, and to provide a fluid sterilization device that retains fluid within the ultraviolet light irradiation range, despite having an extremely simple structure. As a result, according to the present invention, the sterilization efficiency of the fluid can be increased. [Brief explanation of the drawing]

[0015] [Figure 1] A vertical cross-sectional view of the fluid sterilization apparatus according to this embodiment. [Figure 2] A vertical cross-sectional view of the fluid sterilization apparatus according to this embodiment. [Figure 3] (a) Cross-sectional view AA of Figure 1 (cross-sectional view of the first channel), (b) Cross-sectional view BB of Figure 1 (cross-sectional view of the third channel), (c) Cross-sectional view CC of Figure 1 (cross-sectional view of the second channel), (d) Composite cross-sectional view obtained by combining the AA and CC cross-sectional views. [Figure 4] A vertical cross-sectional view of a fluid sterilization device according to Modification 1. [Figure 5] A vertical cross-sectional view of a fluid sterilization device according to modified example 2. [Figure 6](a) Cross-sectional view taken along line D-D of FIG. 5 (cross-sectional view of the first flow path portion), (b) cross-sectional view taken along line E-E of FIG. 5 (cross-sectional view of the second flow path portion). [Figure 7] Vertical cross-sectional view of the fluid sterilization apparatus according to Modification 3.

Mode for Carrying Out the Invention

[0016] [Basic Example] Hereinafter, a fluid sterilization apparatus according to an embodiment of the present invention will be described in detail with reference to the drawings. First, referring to FIGS. 1 to 3, the fluid sterilization apparatus 1 according to this embodiment will be described. Here, FIG. 1 is a vertical cross-sectional view of the fluid sterilization apparatus 1. Further, FIG. 2 is a vertical cross-sectional view of the fluid sterilization apparatus 1 (a view showing the flow of fluid in the fluid sterilization apparatus 1). Furthermore, FIG. 3(a) is a cross-sectional view taken along line A-A of FIG. 1 (cross-sectional view of the first flow path portion including a first communication portion (all of the notch-shaped communication regions) to be described later), FIG. 3(b) is a cross-sectional view taken along line B-B of FIG. 1 (cross-sectional view of the third flow path portion to be described later), FIG. 3(c) is a cross-sectional view taken along line C-C of FIG. 1 (cross-sectional view of the second flow path portion including a second communication portion (all of the notch-shaped communication regions) to be described later), and FIG. 3(d) is a combined cross-sectional view obtained by combining the cross-sectional view taken along line A-A and the cross-sectional view taken along line C-C.

[0017] As shown in FIG. 1, the fluid sterilization apparatus 1 according to this embodiment includes a first flow path portion 10, a light source unit 20 connected to the other end 12 of the first flow path portion 10, a second flow path portion 30 facing the first flow path portion 10 with the light source unit 20 interposed therebetween, and a third flow path portion 40 disposed radially outside the light source unit 20.

[0018] The first flow channel section 10 has one end 11, the other end 12, and a tubular side wall 13, and extends in the axial direction (longitudinal direction). A first communication section 121 is provided at the other end 12 of the first flow channel section 10, which communicates with the third flow channel section 40. When the fluid flowing through the first flow channel section 10 reaches the vicinity of the other end 12, it passes through the first communication section 121 and flows through the third flow channel section 40 (flow channel 41) (see Figure 2). Here, the first communication section 121 in this embodiment corresponds to a plurality of communication areas (notched communication areas) that are cut out from the other end 12 (the connection part with the light source unit 20) toward the one end 11. The shapes (sizes) of the plurality of communication areas may all be the same or they may be different. However, the form of the first communication section 121 is not limited to this.

[0019] Furthermore, although the first channel section 10 in this embodiment is made of polytetrafluoroethylene (PTFE), it is not limited to this. The material of the first channel section 10 may be a resin other than PTFE (for example, perfluoroethylene propene copolymer (FEP), perfluoroalkoxyalkane (PFA), etc.), or a metal such as stainless steel.

[0020] Next, as shown in Figure 1, the light source unit 20 includes a light source 21 that emits ultraviolet light (for example, light having a peak wavelength in the range of 100 nm to 400 nm), a housing 22 that houses the light source 21, and an ultraviolet light-transmitting window 23 (for example, quartz) attached to the housing 22 so as to face the other end 12 of the first flow channel section 10.

[0021] The type of light source 21 is not particularly limited, but examples include semiconductor light-emitting elements such as LEDs (light-emitting diodes) and laser diodes. In addition, although there is one light source 21 in this embodiment, there may be two or more. Furthermore, the light source 21 is mounted on a substrate at a predetermined location inside the housing 22 so as to face the first flow channel 10.

[0022] As shown in Figure 2, ultraviolet light emitted from the light source 21 passes through the ultraviolet light transmission window 23 and is emitted towards the first channel 10. Accordingly, in addition to the straight-traveling light 211 that travels toward one end 11 of the first channel 10, the light source unit 20 also emits wide-angle light 212 that travels diagonally toward the side wall 13 of the first channel 10 and the third channel 30. In the light source unit 20, the surface facing the first channel 10, including the ultraviolet light transmission window 23, may hereafter be referred to as the "ultraviolet light emission surface."

[0023] The relationship between the width W of the ultraviolet light-transmitting window 23 and the inner diameter R1 of the first channel 10 is preferably W > R1 (the width W of the ultraviolet light-transmitting window 23 is greater than the inner diameter R1 of the first channel 10). By setting the relationship between the width W of the ultraviolet light-transmitting window 23 and the inner diameter R1 of the first channel 10 as described above, the fluid flowing through the first channel 10 can receive ultraviolet light irradiated from the ultraviolet light-transmitting window 23 even while passing through the first communication section 121 after reaching the vicinity of the ultraviolet light-transmitting window 23. As a result, the fluid can be irradiated with ultraviolet light for a longer period, and the bactericidal ability of the fluid can be further enhanced. However, the relationship between the width W of the ultraviolet light-transmitting window 23 and the inner diameter R1 of the first channel 10 is not limited to this.

[0024] Next, as shown in Figure 1, the second flow channel section 30 has one end 31, the other end 32, and a tubular side wall 33, and extends in the axial direction (longitudinal direction). Furthermore, a second communication section 311 is provided at one end 31 of the second flow channel section 30, which communicates with the third flow channel section 40. When the fluid flowing through the third flow channel section 40 reaches the vicinity of the one end 31, it passes through the second communication section 311 and flows into the second flow channel section 30 (see Figure 2). Here, the second communication section 311 in this embodiment corresponds to a plurality of communication areas (notched communication areas) that are cut out from one end 31 (the connection part with the light source unit 20) toward the other end 32. The shapes (sizes) of the plurality of communication areas may all be the same, or they may be different. However, the form of the second communication section 311 is not limited to this.

[0025] Furthermore, although the second flow channel 20 in this embodiment is made of PTFE, it is not limited to this. The material of the second flow channel 30 may be a resin other than PTFE (for example, FEP, PFA, etc.) or a metal such as stainless steel.

[0026] Next, the third flow channel section 40 is a tubular member disposed radially outward from the light source unit 20, as shown in Figure 1. In this embodiment, the third flow channel section 40 is connected to the first flow channel section 10 and the second flow channel section 30 via a C-ring, O-ring, or the like. This forms a flow channel 41 that connects the first flow channel section 10 and the second flow channel section 30 and covers the outer periphery of the light source unit 20.

[0027] In other words, after the fluid flowing through the first channel section 10 reaches the vicinity of the light source unit 20, it flows along the ultraviolet light emitting surface of the light source unit 20 and flows into the third channel section 40. As a result, the wide-angle ultraviolet light 212 emitted from the light source unit 20 can be irradiated onto the fluid flowing from the first channel section 10 to the third channel section 40 (see Figure 2).

[0028] Furthermore, the fluid flowing from the first channel section 10 to the third channel section 40 passes through the first connecting section 121 (a notched connecting area). At that time, the fluid flows concentratedly into the first connecting section 121. As a result, turbulence is generated near the first connecting section 121, allowing the fluid to be retained. This allows ultraviolet light to be irradiated for a long time to the fluid flowing from the first channel section 10 to the third channel section 40. This action enhances the bactericidal capacity of the fluid.

[0029] Furthermore, the fluid flowing from the third channel section 40 to the second channel section 30 passes through the second communication section 311 (a notched communication area). At that time, the fluid flows concentratedly into the second communication section 311. As a result, turbulence is generated near the second communication section 311, causing the fluid to accumulate. This allows the fluid in the third channel section 40 to accumulate, and the heat generated by the light source 21 can be efficiently dissipated to the outside of the light source unit 20 via the housing 22 that is in contact with the channel 41.

[0030] Furthermore, it is preferable that the third channel section 40 in this embodiment is made of PTFE, which has high reflectivity characteristics for ultraviolet light. By making the third channel section 40 out of PTFE, the wide-angle light 212 that reaches the third channel section 40 can be repeatedly reflected (see Figure 2). As a result, the fluid flowing through the third channel section 40 can be irradiated with wide-angle light 212 multiple times, thereby further enhancing the sterilization ability of the fluid.

[0031] However, the material of the third flow channel 40 is not limited to this. Other materials may include resins other than PTFE (for example, FEP, PFA, polypropylene (PP), etc.) or metals such as stainless steel.

[0032] By the way, as shown in Figure 3(d), the notched communication area in the first communication section 121 and the notched communication area in the second communication section 311 are arranged alternately in the circumferential direction. More specifically, when the cross section of the first flow channel section 10, which includes the first communication section 121 (all of the notched communication area), and the cross section of the second flow channel section 40, which includes the second communication section 311 (all of the notched communication area), are combined (composite cross section view in Figure 3(d)), the first communication section 121 and the second communication section 311 are arranged in the circumferential direction (for example, clockwise) in the order of first communication section 121a, second communication section 311a, first communication section 121b, second communication section 311b, ..., first communication section 121h, second communication section 311h.

[0033] Here, the flow path 41 of the third flow path section 40 is annular in a cross-sectional view of the third flow path section 40 (see Figure 3(b)). Therefore, fluid that has passed through the first communication section 121 (for example, fluid that has passed through the first communication section 121a) can flow into any of the second communication sections 311 (any of the second communication sections 311a to 311h). At this time, all of the second communication sections 311a to 311h are separated from the first communication section 121a by a predetermined distance in the circumferential direction (the same applies to the other first communication sections 121b to 121h). This effectively prevents short paths of fluid from the first flow path section 10 to the second flow path section 30 via the third flow path section 40. As a result, fluid can be retained near the notched communication area in the first communication section 121. Therefore, since the fluid can be irradiated with ultraviolet light for a long period of time, the sterilization ability of the fluid can be further enhanced.

[0034] [Example 1] Next, with reference to Figure 4, a modified example 1 of the fluid sterilization apparatus according to this embodiment (fluid sterilization apparatus 2) will be described. Here, Figure 4 is a vertical cross-sectional view of the fluid sterilization apparatus 2. As shown in Figure 4, in the fluid sterilization apparatus 2, the second communication portion 312 (notched communication area) is cut out on the light source unit 20 side from the connection portion between the light source unit 20 and the second flow path portion 30 (one end 31). That is, the second communication portion 312 is provided on the light source unit 20 side. In this respect, it differs from the basic example (fluid sterilization apparatus 1) in which the second communication portion 311 was provided in the second flow path portion 30.

[0035] [Differentiation 2] Next, with reference to Figures 5 and 6, a modified example 2 of the fluid sterilization apparatus according to this embodiment (fluid sterilization apparatus 3) will be described. Here, Figure 5 is a vertical cross-sectional view of the fluid sterilization apparatus 3. Also, Figure 6(a) is a DD cross-sectional view of Figure 5 (cross-sectional view of the first flow channel section 10), and Figure 6(b) is an EE cross-sectional view of Figure 5 (cross-sectional view of the second flow channel section 30).

[0036] As shown in Figures 5 and 6, the first communication section 122 provided at the other end 12 of the first flow channel section 10 corresponds to a semi-circular communication area (the length (angle) of the arc is not limited to that shown). Similarly, the second communication section 313 provided at one end 31 of the second flow channel section 30 corresponds to a semi-circular communication area (the length (angle) of the arc is not limited to that shown). In this respect, it differs from the basic example (fluid sterilization device 1) in which the first communication section 121 and the second communication section 311 correspond to multiple notched communication areas.

[0037] [Difference 3] Next, with reference to Figure 7, a modified example 3 of the fluid sterilization apparatus according to this embodiment (fluid sterilization apparatus 4) will be described. Here, Figure 7 is a vertical cross-sectional view of the fluid sterilization apparatus 4. As shown in Figure 7, the relationship between the width W of the ultraviolet light transmission window 23 and the inner diameter R2 of the first flow channel 10 is W ≤ R2 (the width W of the ultraviolet light transmission window 23 is less than or equal to the inner diameter R2 of the first flow channel 10). In this respect, it differs from the basic example (fluid sterilization apparatus 1) in which the relationship between the width W of the ultraviolet light transmission window 23 and the inner diameter R1 of the first flow channel 10 is W > R1.

[0038] Embodiments of the present invention have been described in detail above. However, the foregoing description is intended to facilitate understanding of the present invention and is not intended to limit it. The present invention may include modifications and improvements that can be made without departing from its spirit. Furthermore, the present invention includes equivalents thereof. [Industrial applicability]

[0039] The fluid sterilization device according to the present invention can be used, for example, in ultraviolet light sterilization devices, water purifiers, water heaters, water supply pipes, cooling water circulation devices, water dispensers, beverage dispensers, etc. However, its applications are not limited to these. [Explanation of symbols]

[0040] 1,2,3,4… Fluid sterilizer 10...First channel section 121,122...1st communication part 20…Light source unit 21…Light source 22…Cabinet 23…Ultraviolet light transmission window section 30...Second channel section 311,312,313…Second communication part 40...Third channel section 41...Flow channel of the third flow channel

Claims

1. A first flow channel section extending in the axial direction, through which fluid passes from one end to the other, A light source unit is connected to the other end of the first flow channel and irradiates the fluid with ultraviolet light, A second channel section opposite the first channel section, with the aforementioned light source unit in between, The light source unit is provided with a third flow channel, which is arranged radially outward from the light source unit and is for directing the fluid flowing in the first flow channel to flow in the second flow channel, The first flow channel or the light source unit includes a first communication section that communicates with the third flow channel, The second flow channel or the light source unit is provided with a second communication section that communicates with the third flow channel, The first communication section comprises a plurality of cut-out communication areas that are cut out from the connection section between the first flow path section and the light source unit. Furthermore, the second communication section includes a plurality of notched communication areas that are cut out from the connection section between the second flow path section and the light source unit. A fluid sterilization device characterized in that the notched communication area in the first communication section and the notched communication area in the second communication section are arranged alternately in the circumferential direction.

2. The fluid sterilization apparatus according to claim 1, characterized in that the third channel section is made of polytetrafluoroethylene (PTFE), perfluoroethylene propene copolymer (FEP), perfluoroalkoxyalkane (PFA), or polypropylene (PP).

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